Generally, an air conditioner provides only external motor temperature protection prompts, room temperature display and the like, but no correct feedback information about substantive performances of the air conditioner is provided to users for communication. The users have no way of learning a series of information like whether the air conditioner is in a normal refrigeration state, and whether the use environment is proper, etc. The users just start power-on settings and use the air conditioner; while the air conditioner just operates until a compressor stops operating after a set temperature is reached. After a long time use, the users do not know whether the performance of the air conditioner degrades.